The concept of using pressurized air to inject a fluid through the skin of a human being or an animal is not new. U.S. Pat. No. 3,140,713 to Ismach, for example, discloses a conventional jet injection device with an intradermal nozzle designed to inject fluid at an angle of 45.degree. to control the depth of penetration and prevent tearing or rupturing of the skin. In this regard, it has been found that the pressure entry of liquid into non-fixed, movable soft tissue at various angles creates undesirable tearing, hemorrhage and subsequent post-operative pain. As a result, the use of existing jet injectors have not overcome the physical and psychological traumatic effects of a syringe and needle--particularly in the field of oral injections into mucosa.